According to my interpretation of the rules, you should contact Paris North FIS first, and if contact is not possible with Paris North, you should contact Calais, before switching to LTQ. I know it sounds silly and doesn't happen in practice, but ...
That's exactly what I was getting at.
What I think happens is that provided you have filed a flight plan, ATC is a lot more casual about traffic which did not call them up.
Pre-IR (pre 2006) I did extensive VFR touring around Europe, as far as Crete, and the handovers were always strictly organised. I never tried to go non-radio and it was obvious from the general ATC demeanour down in some of those parts that it would not go down very well. Elsewhere, like UK-France, things are a lot more relaxed, and they have to be because a lot of VFR flight plans get lost anyway.